<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <title>Document</title>
</head>
<body>
  <script>
    function maxNum(num1, num2) {
      if (num1 > num2) {
        return num1;
      } else {
        return num2;
      }
    }
    console.log(maxNum(10, 30));
  </script>
</body>
</html>